When entering a path in the various settings windows, several predefined variables are available to you.  These variables expand to commonly used folder names.  All variables begin with the $ character.  To use  an ordinary $ alone in a folder name, double it: $$

$(AppData)

The application storage area for the current user.  For example: C:\Documents and Settings\John Smith\Application Data\

$(LocalAppData)

The local application storage area for the current user. For example: C:\Documents and Settings\John Smith\Local Settings\Application Data\

$(MyDocuments)

The My Documents folder for the current user.  For example: C:\Documents and Settings\John Smith\My Documents\

$(MyMusic)

The My Music folder in My Documents.  For example: C:\Documents and Settings\John Smith\My Documents\My Music\

$(MyPictures)

The My Pictures folder in My Documents.  For example: C:\Documents and Settings\John Smith\My Documents\My Pictures\

$(ProgramFiles)

The Windows Programs folder.  For example: C:\Program Files\